1. Field of the Invention
The present invention relates to a control apparatus of an electrical rotating machine, which operates to control a power conversion apparatus such as an inverter in order to keep the torque of the electric rotating machine at a command value.
2. Description of Related Art
As such a control apparatus, there is known an apparatus configured to calculate a command current in the d-axis by subtracting a command voltage in the q-axis from the square root of the square of a maximum value of an input voltage of an inverter less the square of a command voltage in the d-axis. For example, refer to Japanese Patent Application Laid-open No. 2006-254572. It is alleged that according to the above control apparatus, it is possible to set the command current in the d-axis to an optimum value during a saturated voltage period in which the voltage to be applied to a motor is at the level of the above maximum value.
However, this conventional control apparatus has a problem in that it cannot perform torque control with a high degree of precision, and is complicated in structure.